/Engine/Source/Runtime/Engine/Classes/Engine/GameInstance.h
IPlatformInputDeviceMapper
virtual void HandleInputDevicePairingChange ( [FInputDeviceId](API\Runtime\Core\Misc\FInputDeviceId) InputDeviceId, [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) NewUserPlatformId, [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) OldUserPlatformId )